1 files changed, 136 insertions, 0 deletions
diff --git a/mailnews/base/util/IOUtils.js b/mailnews/base/util/IOUtils.js
new file mode 100644
index 000000000..ff4eddcdf
--- /dev/null
+++ b/mailnews/base/util/IOUtils.js
@@ -0,0 +1,136 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+this.EXPORTED_SYMBOLS = ["IOUtils"];
+
+Components.utils.import("resource://gre/modules/Services.jsm");
+
+var Cc = Components.classes;
+var Ci = Components.interfaces;
+var kStringBlockSize = 4096;
+var kStreamBlockSize = 8192;
+
+var IOUtils =
+{
+  /**
+   * Read a file containing ASCII text into a string.
+   *
+   * @param aFile  An nsIFile representing the file to read or a string containing
+   *               the file name of a file under user's profile.
+   * @returns A string containing the contents of the file, presumed to be ASCII
+   *          text. If the file didn't exist, returns null.
+   */
+  loadFileToString: function(aFile) {
+    let file;
+    if (!(aFile instanceof Ci.nsIFile)) {
+      file = Services.dirsvc.get("ProfD", Ci.nsIFile);
+      file.append(aFile);
+    } else {
+      file = aFile;
+    }
+
+    if (!file.exists())
+      return null;
+
+    let fstream = Cc["@mozilla.org/network/file-input-stream;1"]
+                    .createInstance(Ci.nsIFileInputStream);
+    // PR_RDONLY
+    fstream.init(file, 0x01, 0, 0);
+
+    let sstream = Cc["@mozilla.org/scriptableinputstream;1"]
+                    .createInstance(Ci.nsIScriptableInputStream);
+    sstream.init(fstream);
+
+    let data = "";
+    while (sstream.available()) {
+      data += sstream.read(kStringBlockSize);
+    }
+
+    sstream.close();
+    fstream.close();
+
+    return data;
+  },
+
+  /**
+   * Save a string containing ASCII text into a file. The file will be overwritten
+   * and contain only the given text.
+   *
+   * @param aFile   An nsIFile representing the file to write or a string containing
+   *                the file name of a file under user's profile.
+   * @param aData   The string to write.
+   * @param aPerms  The octal file permissions for the created file. If unset
+   *                the default of 0o600 is used.
+   */
+  saveStringToFile: function(aFile, aData, aPerms = 0o600) {
+    let file;
+    if (!(aFile instanceof Ci.nsIFile)) {
+      file = Services.dirsvc.get("ProfD", Ci.nsIFile);
+      file.append(aFile);
+    } else {
+      file = aFile;
+    }
+
+    let foStream = Cc["@mozilla.org/network/safe-file-output-stream;1"]
+                     .createInstance(Ci.nsIFileOutputStream);
+
+    // PR_WRONLY + PR_CREATE_FILE + PR_TRUNCATE
+    foStream.init(file, 0x02 | 0x08 | 0x20, aPerms, 0);
+    // safe-file-output-stream appears to throw an error if it doesn't write everything at once
+    // so we won't worry about looping to deal with partial writes.
+    // In case we try to use this function for big files where buffering
+    // is needed we could use the implementation in saveStreamToFile().
+    foStream.write(aData, aData.length);
+    foStream.QueryInterface(Ci.nsISafeOutputStream).finish();
+    foStream.close();
+  },
+
+  /**
+   * Saves the given input stream to a file.
+   *
+   * @param aIStream The input stream to save.
+   * @param aFile    The file to which the stream is saved.
+   * @param aPerms   The octal file permissions for the created file. If unset
+   *                 the default of 0o600 is used.
+   */
+  saveStreamToFile: function(aIStream, aFile, aPerms = 0o600) {
+    if (!(aIStream instanceof Ci.nsIInputStream))
+      throw new Error("Invalid stream passed to saveStreamToFile");
+    if (!(aFile instanceof Ci.nsIFile))
+      throw new Error("Invalid file passed to saveStreamToFile");
+
+    let fstream = Cc["@mozilla.org/network/safe-file-output-stream;1"]
+                    .createInstance(Ci.nsIFileOutputStream);
+    let buffer  = Cc["@mozilla.org/network/buffered-output-stream;1"]
+                    .createInstance(Ci.nsIBufferedOutputStream);
+
+    // Write the input stream to the file.
+    // PR_WRITE + PR_CREATE + PR_TRUNCATE
+    fstream.init(aFile, 0x04 | 0x08 | 0x20, aPerms, 0);
+    buffer.init(fstream, kStreamBlockSize);
+
+    buffer.writeFrom(aIStream, aIStream.available());
+
+    // Close the output streams.
+    if (buffer instanceof Components.interfaces.nsISafeOutputStream)
+      buffer.finish();
+    else
+      buffer.close();
+    if (fstream instanceof Components.interfaces.nsISafeOutputStream)
+      fstream.finish();
+    else
+      fstream.close();
+
+    // Close the input stream.
+    aIStream.close();
+    return aFile;
+  },
+
+  /**
+   * Returns size of system memory.
+   */
+  getPhysicalMemorySize: function() {
+    return Services.sysinfo.getPropertyAsInt64("memsize");
+  },
+};